Ingredients of food products, often in the form of a slurry, are sometimes sprayed onto an edible base or substrate. Examples of such sprayed ingredients are chocolate, cheese, sugar and various seasoning coatings for chips.
Spraying is usually accomplished by a device known as an enrober, and exemplary enrobers are described in U.S. Pat. Nos. 4,193,373 and 4,283,012. The enrober typically includes an array of nozzles so as to cover as many surface planes as desired. The overspray is constantly collected and recirculated.
Typically the ingredient is supplied from an ingredient tube to an inner orifice of each nozzle. Low pressure air flowing through a surrounding outer orifice propels the ingredient. Blockage of the inner orifice by accumulated and solidified ingredient is a recurring problem. One solution is to provide a cleanout plunger that periodically reciprocates into the inner orifice, as described in U.S. Pat. No. 4,283,012. However, it is still of great importance to be able to readily disassemble the nozzle rather completely for thorough periodic cleaning. Ease of disassembly is also important because of the need to inspect and replace worn components. Particularly in the case of more complex nozzles having cleanout plungers, it is difficult to arrive at an easily disassemblable construction.
The rate at which the ingredient is sprayed through a particular nozzle is not adjustable over a wide range. Generally, the principal parameter that can be varied to influence this rate is the air pressure, but the nozzle will not perform satisfactorily and the optimum spray pattern cannot be maintained if the pressure is changed substantially.
A principal objective of the present invention is to provide a spray apparatus for an enrober that is readily disassemblable for cleaning and for replacement of parts. Another objective is to provide such an apparatus in which the size of the inner orifice can be readily changed to adjust the rate of ingredient spray. Still another objective is to provide these advantages in an apparatus that includes a reciprocating cleanout plunger.